Blasters are common small arms used in Star Wars. The firepower of hand-held blasters varies, and at least some blasters have adjustable power settings. High-powered blasters can blow large chunks out of concrete walls (or to be precise -- its material equivalent in the worlds of Star Wars), while low-powered blasters may only cause survivable wounds. Some blasters have a "stun" setting.
Blasters range in size from heavy support weapons that are mounted on vehicles and tripods to hold-out weapons no bigger than a human hand. From handguns to rifles, they vary in application, and usually the larger the weapon the more options it has available. There is a dedicated version of the tripod-mounted E-Web Heavy Blaster that is distributed to local police forces that only has a stun setting known as a Riot Gun that can easily subdue large crowds.
Blaster cannons are heavier grades of blaster used as primary armament on vehicles. Luke Skywalker referred to his modified airspeeder as using blasters, and the Z-95 Headhunter (a snub fighter precursor to the X-wing) uses triple-blasters in its wings as its primary weapons.
Differences from Turbolasers
Blasters are commonly thought of as small-scale turbolasers. However, blasters do not appear to be lightspeed weapons, although some evidence exists for their having an invisible damaging component that is just ahead of a visible bolt of waste energy.